powerfun-unity/Assets/AR/ARGameObjectFactory.cs

using UnityEngine;
using UnityEngine.Rendering;

namespace Assets.AR
{
    public static class ARGameObjectFactory
    {
        private static bool IsValidVertex(Vector3 v) => !float.IsNaN(v.x) && !float.IsInfinity(v.x) && !float.IsNaN(v.y) && !float.IsInfinity(v.y) && !float.IsNaN(v.z) && !float.IsInfinity(v.z);
        //创建轨迹
        public static GameObject CreateTrajectory(
            ARRoute route,
            int segment,
            float lOffset,
            float rOffset,
            float margin = float.NaN)
        {
            int start;
            int end;
            route.GetSlamSegmentRange(segment, out start, out end);
            
            var num1 = end - start + 1;
            var indices = new int[(num1 - 1) * 6];
            var vector3Array1 = new Vector3[num1 * 2];

            Vector3 left, right;
            CreateVertices(start, route, lOffset, rOffset, out left, out right, margin);
            vector3Array1[0] = left;
            vector3Array1[1] = right;
            
            var num2 = 2;
            var num3 = 0;
            for (var frame = start + 1; frame <= end; ++frame)
            {
                CreateVertices(frame, route, lOffset, rOffset, out left, out right, margin);
                if (IsValidVertex(left) && IsValidVertex(right))
                {
                    var vector3Array2 = vector3Array1;
                    var index1 = num2;
                    
                    var num4 = index1 + 1;
                    var vector3_1 = left;
                    vector3Array2[index1] = vector3_1;
                    var vector3Array3 = vector3Array1;
                    
                    var index2 = num4;
                    num2 = index2 + 1;
                    var vector3_2 = right;
                    vector3Array3[index2] = vector3_2;
                    var numArray1 = indices;
                    
                    var index3 = num3;
                    var num5 = index3 + 1;
                    var num6 = num2 - 3;
                    numArray1[index3] = num6;
                    var numArray2 = indices;
                    
                    var index4 = num5;
                    var num7 = index4 + 1;
                    var num8 = num2 - 4;
                    numArray2[index4] = num8;
                    var numArray3 = indices;
                    
                    var index5 = num7;
                    var num9 = index5 + 1;
                    var num10 = num2 - 1;
                    numArray3[index5] = num10;
                    var numArray4 = indices;
                    
                    var index6 = num9;
                    var num11 = index6 + 1;
                    var num12 = num2 - 4;
                    numArray4[index6] = num12;
                    var numArray5 = indices;
                    
                    var index7 = num11;
                    var num13 = index7 + 1;
                    var num14 = num2 - 2;
                    numArray5[index7] = num14;
                    var numArray6 = indices;
                    
                    var index8 = num13;
                    num3 = index8 + 1;
                    var num15 = num2 - 1;
                    numArray6[index8] = num15;
                }
            }

            var mesh = new Mesh
            {
                vertices = vector3Array1,
                indexFormat = IndexFormat.UInt32
            };
            mesh.SetIndices(indices, MeshTopology.Triangles, 0);
            var trajectory = new GameObject(string.Format("Segment {0}", (object)segment), new System.Type[3]
            {
                typeof(MeshFilter),
                typeof(MeshRenderer),
                typeof(MeshCollider)
            });
            trajectory.GetComponent<MeshFilter>().sharedMesh = mesh;
            trajectory.GetComponent<MeshCollider>().sharedMesh = trajectory.GetComponent<MeshFilter>().sharedMesh;
            return trajectory;
        }

        private static void CreateVertices(
          int frame,
          ARRoute route,
          float lOffset,
          float rOffset,
          out Vector3 left,
          out Vector3 right,
          float margin = float.NaN)
        {
            var trajectoryOrientationAt = route.GetTrajectoryOrientationAt(frame);
            var vector3 = route.GetCameraPositionAt(frame) - trajectoryOrientationAt * Vector3.up * route.CameraHeight;
            
            if (lOffset == 0.0)
                lOffset = route.GetLeftSideOffset((float)frame);
            
            if (float.IsNaN(margin))
                lOffset += route.RouteMargin;
            else
                lOffset += margin;
            
            left = vector3 + trajectoryOrientationAt * Vector3.left * lOffset;
            
            if (rOffset == 0.0)
                rOffset = route.GetRightSideOffset((float)frame);
            
            if (float.IsNaN(margin))
                rOffset += route.RouteMargin;
            else
                rOffset += margin;
            
            right = vector3 - trajectoryOrientationAt * Vector3.left * rOffset;
            left.y = right.y = vector3.y;
        }
    }
}